1. Field of the Invention
The present invention relates to an optical fiber cord comprising a plastic optical fiber comprising a core and a cladding, and a jacket layer provided on the optical fiber, and, more particularly, to a plastic optical fiber cord with excellent flame retardance.
2. Description of the Related Art
Inorganic glass optical fibers have been known as optical fibers which are excellent in light transmission properties over a broad range of wavelengths. However, since said glass optical fibers do not have good processability or flexural strength, plastic optical fibers were developed and have been widely used as optical fibers.
These plastic optical fibers are basically comprised of a core polymer comprising a polymer which has excellent light transmission properties and a high refractive index, such as polymethyl methacrylate (hereinafter referred to as PMMA), polycarbonate (hereinafter referred to as PC), and a clad polymer comprising a transparent polymer which has a refractive index lower than that of the core polymer, such as fluorine-containing polymers.
Known examples of the plastic optical fibers of this type are optical fiber strands, bulk fibers made by covering optical fiber strands with a functional protective layer, optical fiber cords made by covering optical fiber strands with a jacket, bundled fibers made of an assembly of bulk fibers, and optical fiber cables made by applying tension members to the bulk fibers.
For the jacket material these all-plastic optical fiber cords use a vinyl chloride resin containing a plasticizer of not less than 10 wt %, or a polyethylene. Because these fiber cords have a low capacity for flame retardance, their applications are limited.